Burglar-proof lock



June 19, 1962 J. M. AGNEVSE 3,039,807

BURGLAR-PROOF LOCK Filed Feb. 28, 1961 Fig.1-

INVENTOR. JOSEPH MAGNESE ATTORNEY United States atent 3,039,807 BURGLAR-PROOF LOCI Joseph M. Agnese, 2770 Greenwich St., San Francisco, Calif.

Filed Feb. 28, 1961, Ser. No. 92,347 2 Claims. (Cl. 292-346) This invention relates to improvements in door locks and more particularly to a retractile lock bolt having novel means for preventing the retraction thereof from without by means other than a key fitting in the lock.

Many types of door locks now in use are easily opened from without by sliding the lock bolt backwardly by means of a thin blade projected inwardly against the head of such bolt through the space between the closed door and the door frame. While various methods and devices have been devised to prevent the opening of door locks by such means, none have been entirely satisfactory or reasonably priced.

The present invention has for its primary object the provision of an improved burglanproof door lock of the type having a retractable bolt which is equipped with a novel safety device for preventing the retraction of the bolt by means of a blade or other instrument inserted between the door and the door frame. One of the advantages of a lock bolt embodying the present invention may be attributed to the fact that when the door is closed, the safety device is securely held in a position preventing the complementary curved surfaces of the head of such lock bolt and the safety device from being engaged by a blade projected into the space between the door and the door frame.

Other and further objects of my invention will be pointed out hereinafter or will be indicated in the appended claims or will be obvious to one skilled in the art upon an understanding of the present disclosure. For the purpose of this application, I have elected to show herein certain details of a door lock which is representative of my invention; it is to be understood. however, that the embodiment of my invention herein shown and described is for purposes of illustration only and that it is not to be regarded as exhaustive of the variations of the invention in the art.

In the accompanying drawing:

FIG. 1 is a rear view showing a lock embodying my invention mounted on a door which is partially open;

FIG. 2 is a plan view of the lock, showing the door partially open and the lock bolt in section;

FIG. 3 is a similar view showing the door in a closed position;

FIG. 4 is an end view of the lock; and

FIG. 5 is an enlarged composite view of the lock bolt and the safety device.

Referring to the drawing, the numeral 1 designates a conventional door mounted for swinging movement on one of two vertical frame members 2. Secured as by screws to the other frame member 2 is a bolt receiving keeper fixture 3 of the kind usually employed in combination with dead-locks to receive and securely hold the head of a retractile bolt when the door is closed. The fixture 3 is provided with an open cavity or recess adapted to receive the head of a lock bolt, and the rear side 3a of such fixture is preferably formed with an inwardly sloping striker surface 4 that terminates at the inner edge 3b of such rear side.

Mounted on the rear or inner side of the door 1 adjacent the outer vertical edge thereof and in a position in substantially horizontal alignment with the fixture 3 is a lock casing 5 which contains the assembled parts of a suitable lock, one of such parts being a retractile spring actuated bolt 6 having an enlarged head 7 adapted to ice project outwardly beyond the lock casing. The head 7 of the bolt is also adapted to enter the cavity of the fixture 3 when the door is closed. The rear side of the head 7 of the bolt is adapted to engage with the inner surface of the rear side 3a of the keeper fixture to normally prevent the opening of the door after it has been closed. The head 7 of the bolt is formed in the usual manner with an arcuate or other suitably shaped cam face or surface at its forward side, which, when brought into engagement with the sloping striker surface 4 of the keeper fixture 3, as the door is closed, makes possible the application of a suitable pressure on the bolt to retract the same and allow the door to close fully. The bolt is retracted against the pressure of a suitable compression spring 6a, and such spring functions in the usual manner to return the bolt to a position wherein its head 7 extends outwardly from the lock casing 5 and into the cavity of the keeper fixture 3. The bolt 6 is adapted to be retracted from within by manipulating a knob 8, and a key fitting in the lock is adapted to retract the bolt from without. The lock mechanism thus described is commonly found in door locks of the type now in use, and no claim is made thereto.

The head 7 of the lock bolt 6 is formed with a large cavity 7a which opens forwardly. Loosely fitting in the cavity 7a and mounted on a vertical pivot pin 9 is a pivoted member 10 which has an outer or forwardly disposed curved or sloping surface 10a which conforms substantially to the curvature or shape of the forward side of the head 7 of the bolt 6. The cavity 7a of the bolt head 7 is closed at its rear side by a vertical wall 7b which forms a part of the head, and narrow upper and lower walls 7c, 70 closing the upper and lower ends of the cavity also constitute integral portions of the head. The ends of the pivot pin 9 are anchored on the upper and lower walls 70, 7c. The pivoted member 10 is mounted at its enlarged end portion on the pivot pin 9, and such member is adapted to swing back and forth between a position within the cavity wherein the outer curved or sloping surface is a continuation of the curved or sloping surface of the bolt head to a position wherein a substantial portion thereof projects forwardly beyond such curved surface of the head. When the pivoted member 10 is positioned with its forward end portion projecting beyond the bolt head 7, the inner side portion of the cavity 7a is opened sufficiently to allow a blade or other thin implement, when inserted rearwardly between the vertical outer edge of the closed door 1 and the adjacent door frame 2, to strike against the vertical wall 7b rather than against the curved outer surface of such pivoted member. Thus, when the pivoted member 10 is swung outwardly, as will be presently described, neither the curved forward surface of the bolt head 7 nor the outer curved surface 10a of the pivoted member can be engaged by a blade or other implement to exert a pressure on the bolt head such as would cause a retraction of the lock bolt 6 to allow the door to be opened.

Secured to the enlarged rear end of the pivoted member 10 is a structurally rigid pin or projecting member 11 which extends rearwardly at right angles to the pivot pin 9 through a horizontal open slot 12 in the head 7 of the bolt 6. The outer free end portion of the structurally rigid pin 11 is adapted to enter a shallow groove 13 in the lock casing 5. When the door 1 is swung forwardly toward its closed position, the curved or sloping sides of the head 7 of the bolt and the pivoted member 10 come into contacting relationship with the sloping striker surface 4 of the keeper fixture 3, and by reason of the inward pressure thereby exerted on the bolt head as the door continues to close, the bolt will be continuously retracted until the outer end thereof reaches the inner edge 3b of the rear side 3a of the keeper fixture, at which time the bolt head area-e? will be free to be actuated outwardly by the locks compression spring 6a and into the open cavity of such fixture. As the bolt 6 and its head 7 move outwardly to the right (FIG. 3), the outer free end portion of the pin 11 is carried into engagement with the inner edge 31) of the rear side 3a of the keeper fixture 3, and since any further outer movement of such free end portion of the pin is thereby discontinued while the bolt head and the pivoted member 10 continue to move outwardly, the said pivoted member will be turned about the pivot pin 9 so as to swing the forward or smaller end of the pivoted member outwardly to a position whereby a blade projected rearwardiy between the door and the frame 2 will engage with the vertical wall 7b rather than with the curved or sloping outer surfaces of either the bolt head or the pivoted member. When the bolt head 7 has concluded its outward movement into the cavity of the keeper fixture 3, the outer end portion of the pin 11 will have entered the open shallow groove 13 in the lock casing 5, and such pin will be securely held therein by the inner edge 3b of the rear side 3a engaging with the pin. With the pin 11 being thus secured against movement, the pivoted member 10 will continue to be held in a position wherein its curved'or sloping outer surface cannot be contacted by a blade or the like projected rearwardly between the door and the frame member 2. The lock is thereby prevented from being opened from without except by a key.

What I claim is: j

1. In a door lock, a lock casing secured to and carried by a swinging door, a keeper fixture secured to a door frame and having a striker surface and a recess, a retractable bolt carried by the casing and having a projecting head adapted to extend into the recess when the door is in a closed position, the bolt head having a forwardly disposed cam face adapted to engage with the striker surface when the door is moved toward a closed position, the bolt head having a slotted horizontal end opening and a cavity opening forwardly at the cam face, a pivoted member carried by the bolt head and having a cam. face adapted to complement the cam face of the bolt head, the pivoted member fitting in the cavity and mounted on the bolt head for swinging movement about a vertical axis to a position wherein a portion thereof projects forwardly beyond the forwardly disposed cam face of the bolt head and the cavity is opened, a structurally rigid member formed integrally with and extending rearwardly from the pivoted member, the structurally rigid member movably extending through the slotted end opening of the bolt head and having an end portion projecting rearwardly beyond such head and adapted to strike against the keeper fixture as the bolt head enters the recess of the fixture when the door is closed, whereby the pivoted member is swung to a position opening the cavity.

2. In a door lock, a locking bolt having a head, the head having a horizontally extending open slot, a cavity opening forwardly and a forwardly disposed cam surface, a pivoted member carried by the head and mounted at its rear end for pivotal movement about a vertical axis, the pivoted member having a forward cam surface conforming generally to and complementing the cam surface of the head, the said pivoted member being normally positioned with its cam surface conforming to the cam surface of the head and the said pivoted member normally closing the cavity, the pivoted member being pivotally adjustable to a position wherein its forward end portion projects substantially beyond the forward cam surface of the head whereby the cavity is open, a structurally rigid pin formed integrally with and projecting rearwardly from the rear end of the pivoted member and arranged at right angles to the axis, the pin movably extending through the slot in the head and rearwardly beyond the rear side of the head.

References Cited in the file of this patent UNITED STATES PATENTS 1,246,588 Goshie Nov. 13, 1917 2,107,300 Kilpatrick Feb. 8, 1938 2,350,306 Spain May 30, 1944 

